diff --git a/coinone/api/common/enums.py b/coinone/api/common/enums.py
index 8dfb7c3..cf2d876 100644
--- a/coinone/api/common/enums.py
+++ b/coinone/api/common/enums.py
@@ -17,7 +17,7 @@ class Currency(str, enum.Enum):
     KRW = 'krw'
 
 
-class OrderType(int, enum.Enum):
+class OrderType(enum.IntEnum):
     Ask = 1
     Bid = 0
     Sell = 1